Improvement in steam-boilers



llnte tant para einer.

Letters Patent'No. 96,885, dated November 16, 1869.

IMPROVEMENT IN STEAM-BOILERS.

l MOH- The Schedule referred to in these Letters Patent and making part f the same I, GEORGE CLARK, of the city of Buffalo, in the county of Erie, and State of New York, have invented a certain new and useful Improvement in Steam-Boilers, of which the following is a specification.

In steam-generators, as ordinarily constructed, the water is heated and'maintained at a uniform, or nearly-uniform temperature throughout the different portions of the boiler. Y

In'such case it is evident'that when the temperature of the ues is reduced to nearly the temperature of the water surrounding them, the further absorption and utilization of heat therefrom cease.

The object of my invention is to utilize this waste heat.

The improvement relates to that class of boilers which is provided with return. fines, arranged below the direct ues, .So that the products of oombustion are compelled to descend from one due to the other, the lower ues being the last ones through which the draught passes before entering the smokestack.

My invention consists in so dividing the wat-erspace of such a boiler, and arranging the mout-h of the feed-water pipe, that it will open up into the boiler near the up-take, and thereby compel the water, before it reaches the top, to circulate `back and forth along the fluesiu a reverse .direction from the draught within. This causes thetemperature of the water to increase as it ascends, it being subjected to the most intense heat from the furnace near the top and steam-generating surface, while its temperature decreases toward the bottom as the heat of the fines diminish, until the flues through which the products of combustion last pass are surrounded by comparatively cold water, which continues to absorb the heat therefrom until they enter the smokestack.

'In the accompanying drawings- Figure I is a longitudinal vertical section of my improved boiler, with the 11p-take at one corner.

Figure II is a cross-section of the same.

Figure III a longitudinal section, with the np-take at the end of the boiler.

Like letters of reference designate like .parts in each of the figures.

A represents the furnace. I5, the direct, B1, the return, and B2, the rfc-direct fines.

(l, the 11p-take.

(l d', two horizontal 'plates dividing the water-space into three compartments, E E1 E2.

rIhe plate l is an extension of the bottom plate of the furnace, which reaches to near the rear end 5 a space, f, being left for the passage of the water from the middle to the upper compartment.

The diaphragm df extends from the rear of the water-space to near the front end; a space, f', similar to f, permitting free passage of the water from the lower to the middle compartment.

G is the mouth of the feed-water pipe, opening up into the boiler at the rear ond, as shown.

In Figs. I and I-I, H is a damper, opening into the up-take at the rear of the direct dues, which can be opened, in firing up, so as to produce a direct draught to thc vsmoke-stack, without the products of combustion passing through the return and re-direct fines'.

Fig. III shows a form of boiler which may be used where there is not sufficient width of space for the arrangement shown in the other figures.

In this figure the up-take is at the end of the boiler, with a water-jacket, I, intervening it and a flue-chamber, J, at the end of the flues.

A passage, K, is provided through this jacket, closed by a damper, H', which permits of a direct communication to the 11p-take, similar to that alforded by thedamper H, in Figs. I and II.

The direction of the draught through the different flues is shown by the wave lines, while the arrows denote the reverse course which the Water is compelled to take to reach the top of the boiler.

The len'iployment of the division-plates ll ll has the effect to divide the boiler into two heating and. one steam-generating space; the circuitous course which the vwater has to take preventing it reaching the upper compartment before being properly heated.

The effect of this is to prevent that reduction and change of temperature in the upper and steamspace which takes place on the introduction of a fresh suppply of water, as the ordinary general circulation from one compartment is prevented bythe division-plates.

When the Water-space is undivided, a more or less violentag'itation is maintained, causing a constant circulation between the top and bottom, which carries up the dirt or other sedimenti'u the water, and deposits it on the fines.

By my improved construction, this agitation at the bottom is prevented, while the slow horizontal movement of the water facilitates the deposition ofthe sediment on the bottom of the boiler or on the top of the lower diaphragm-plate.

This division of the water-space also renders the upper portion, which is subjected to'the most intense heat, `a superior steam-generating chamber, while the comparatively low temperature of the botalong the ues, in a direction reverse from that of the draught therein, substantially as and for the p urposes hereinbefore set forth,

NTitnesses:

JAY HYATT, J No. J. BONNER.

GEORGE CLARK. 

